62 research outputs found

    Hydraulic characteristics of the airlift pump

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    Airlift pumps are the simplest devices used for lifting and transporting of liquid in water and wastewater systems. They constitute the subject of interest in numerous studies, focusing on their two-phase flow. The knowledge of two-phase flow parameters is necessary for the correct design of an airlift pump. In the available literature on the subject, one will find numerous models describing the two-phase gas-liquid flow. One of the most popular is the Zuber – Findlay model, also called the slip model. The subject of the present research consisted in a vertical bubble column, with the diameters of 50 and 75 mm, used to transport the water-air mixture. Based on the results of the laboratory experiments the hydraulic characteristics were developed: liquid flow depending on the depth Hs and the air flow Qp. For the mathematical description, second-degree polynomial model was applied, as well as and assessment of the determination coefficient was performed. Efficiency factors of the airlift pump and other parameters for two-phase mixture during the airlift pump’s operation were determined using the slip model. Based on the experiment, it has been found for both of the analysed diameters that the efficiency of the airlift pump increased along with the depth Hs and the air flow Qp. The airlift pump achieves maximum liquid efficiency within a specified range of the immersion depth. In a small diameter airlift pump (50 mm), slug and plug flow regimes are predominant

    Periostin in exhaled breath condensate and in serum of asthmatic patients : relationship to upper and lower airway disease

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    PURPOSE: Periostin is considered a biomarker for eosinophilic airway inflammation and have been associated with NSAID-Exacerbated Respiratory Disease (NERD) and chronic rhinosinusitis (CRS). In this study, we aimed to evaluate periostin in exhaled breath condensate (EBC) and in serum of patients with various asthma phenotypes. METHODS: The study included 40 asthmatic patients (22 with NERD) and 17 healthy controls. All the procedures (questionnaire, spirometry, FeNO, nasal swabs, EBC collecting, and blood sampling) were performed on the same day. Periostin concentrations were measured using an ELISA kit. RESULTS: Periostin was detected in EBC from 37 of 40 asthmatics and in 16 from 17 of controls. The concentration of periostin in EBC did not differ between the study groups and was not associated with NERD or asthma severity. However, the EBC periostin was significantly higher in asthmatics with CRS as compared to those without (3.1 vs 2 ng/mL, P=0.046). Patients with positive bacterial culture from nasal swabs had higher EBC periostin concentrations than those without (3.2 vs 2.1 ng/mL; P=0.046). The mean serum periostin level was higher in asthmatics with a 1-year history of exacerbation than in those without (3.2 vs 2.3 ng/mL, P=0.045). Asthmatics with skin manifestation of NSAIDs hypersensitivity had higher serum periostin levels as compared to those without (3.5 vs 2.3 ng/mL; P=0.03). CONCLUSIONS: EBC periostin levels seem to reflect intensity of upper airway disease in asthmatics, while serum levels of periostin are associated with asthma activity (exacerbations or FeNO) or NERD subphenotypes

    Idiopathic pulmonary fibrosis - novel approach on future treatment

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    IntroductionIdiopathic pulmonary fibrosis (IPF) is a fatal pulmonary disease that leads to progressive fibrosis and extremely poor resaults.. Since the etiology is unknown, there are highly limited options of the IPF treatment. The researchers are trying to discover the most valuable targets, leading them to the agents registered in different conditions or not registered as any other treatment. This innovative approach can result in IPF being determined as not fatal. PurposeThe purpose of our review is to present possible future treatment of idiopathic pulmonary fibrosis and point out the promising targets that could lead the researchers to the development of better IPF management. Materials and methodsWe have reviewed the literature from the PubMed database searching for clinical trials, meta analysis and randomized controlled trials from the past 5 years. The keywords we agreed on offered us the most informative articles and made us hope for the further development of our article. ResultsOur review shows that there are new targets that could significantly benefit IPF treatment. However, the means we presented in our review need more research to prove its safeness, effectiveness in slowing down the decline of the FVC, improving patients’ physical efficiency, their saturation level and most importantly their ability to stop the continuous fibrosis of the lungs. ConclusionsThe only treatment registered for IPF are nintedanib and pirfenidone, but the researchers continue the exploration of new possible measures to improve the survival rate and quality of life of the patients suffering from this fatal disease

    Fe-modified Mn2CuO4 spinel oxides: coatings based on abundant elements for solid oxide cell interconnects

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    The current state of the art steel interconnect coating materials are based on critical raw material - Co-oxide spinels. Replacing Co-oxide spinels with alternative, abundant materials can reduce the dependence on the critical raw materials. Cobalt-free coatings with the general formula Mn2-xCuFexO4, where x = 0, 0.1, 0.3, were electrophoretically deposited on a ferritic stainless-steel support and evaluated. Prior to deposition, the powders were prepared by a soft chemistry process and studied in terms of crystallographic phase analysis, electrical conductivity, thermal expansion, and sinterability behaviour. Coated steel samples were oxidised in an air atmosphere at 750 \ub0C for 3000 h. In parallel, a state-of-the-art MnCo2O4 spinel oxide was tested as a reference. The coatings and oxide scale microstructures of the surfaces and cross-sections were examined by XRD, and SEM-EDX. TEM-EDX, XRF, and micro-XRD were also performed on the cross-section lamellae. The electrical properties of the steel-coating system were evaluated by Area Specific Resistance measurement. The results confirm that Mn–Cu–Fe oxides exhibit higher conductivity and lower TEC than Mn–Co oxide. Based on the obtained results, it might be concluded that the proposed coatings are a promising alternative to coatings that contain cobalt

    Causes of runner’s diarrhea and dietary recommendations to avoid it - systematic review

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    Complaints of diarrhea and other gastrointestinal symptoms are common among endurance runners. These problems may interfere with athletic activities and be the main cause of underperformance during sports events. It is estimated that this difficulty affects 30 to 90 percent of long-distance runners. The most important pathophysiological factors affecting the occurrence of gastrointestinal symptoms are ischemia and mechanical damage to the intestines, as well as the secretion of neuroendocrine substances. The diet before physical exercise is also one of the most significant factors related to the appearance of gastrointestinal symptoms. Avoiding the intake of fat, caffeine, protein, fiber, non-steroidal anti-inflammatory drugs and dehydration before performance is one of the suggestions for preventing runner’s diarrhea. There are new recommendations for athletes, such as avoidance of fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs) and the intake of multiple transportable carbohydrates. It seems that a short-term gluten free diet has no effect on the performance of athletes but further research is needed. Mechanisms of runner’s diarrhea are still poorly understood, so more research needs to be conducted to improve the recommendations to runners.&nbsp

    Synthesis and Investigation of Anti-tumor Properties of Novel, Bicyclic Furopyrimidine, Pyrrolopyrimidine and Pyrimidopyridazine Nucleoside Analogues

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    A series of nine hitherto unknown bicylic pyrimidine nucleoside analogues (BCNAs) bearing bicyclic furo[2,3-d]pyrimidin-2(3H)-one, 3H-pyrrolo[2,3-d]pyrimidin-2(7H)-one and 5,6-dihydropyrimido[4,5-c]pyridazin-7(8H)-one bases were prepared in a straightforward approach. The synthesised compounds posses ÎČ-D-rybofuranose or ÎČ-D-2-deoxyrybofuranose or ÎČ-D-arabinofuranose moieties attached to each of the heterocylic ring systems. This is one of a few examples of synthesis of pyrrolo[2,3-d]pyrimidin-2(7H)-one and dihydropyrimido[4,5-c]pyridazin-7(8H)-one nucleosides, and the first example of such nucleosides possessing arabinose moiety. A key synthetic step was a Sonogashira coupling reaction. For coupling with 4-phenyl-1-butyne, we used deprotected 5-iodouridine, 2’-deoxy-5-iodouridine, and 5-iodoarabinouridine and this reaction was followed by cycloisomerization and subsequent conversion of the furane ring into a pyrole ring or a pyridiazine. This approach resulted in the creation of small library of compounds, which were evaluated for their antiproliferative properties against HL-60 and Jurkat E6.1 cell lines. Of all tested compounds, only 3-(ÎČ-D-rybofuranosyl)-6-(2-phenylethyl)furo[2,3-d]pyrimidin-2(3H)-one exhibited weak anti-proliferative activity, with IC50 values of 54 and 81 ”M for HL-60 and Jurkat E6.1 cells, respectively

    Evaluation of annoyance from the wind turbine noise: A pilot study

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    Objectives: The overall aim of this study was to evaluate the perception of and annoyance due to the noise from wind turbines in populated areas of Poland. Material and Methods: The study group comprised 156 subjects. All subjects were asked to fill in a questionnaire developed to enable evaluation of their living conditions, including prevalence of annoyance due to the noise from wind turbines and the self-assessment of physical health and well-being. In addition, current mental health status of the respondents was assessed using Goldberg General Health Questionnaire GHQ-12. For areas where the respondents lived, A-weighted sound pressure levels (SPLs) were calculated as the sum of the contributions from the wind power plants in the specific area. Results: It has been shown that the wind turbine noise at the calculated A-weigh­ted SPL of 30-48 dB was noticed outdoors by 60.3% of the respondents. This noise was perceived as annoying outdoors by 33.3% of the respondents, while indoors by 20.5% of them. The odds ratio of being annoyed outdoors by the wind turbine noise increased along with increasing SPLs (OR = 2.1; 95% CI: 1.22-3.62). The subjects' attitude to wind turbines in general and sensitivity to landscape littering was found to have significant impact on the perceived annoyance. About 63% of variance in outdoors annoyance assessment might be explained by the noise level, general attitude to wind turbines and sensitivity to landscape littering. Conclusions: Before firm conclusions can be drawn further studies are needed, including a larger number of respondents with different living environments (i.e., dissimilar terrain, different urbanization and road traffic intensity)

    Causes of runner’s diarrhea and dietary recommendations to avoid it - systematic review

    Get PDF
    Complaints of diarrhea and other gastrointestinal symptoms are common among endurance runners. These problems may interfere with athletic activities and be the main cause of underperformance during sports events. It is estimated that this difficulty affects 30 to 90 percent of long-distance runners. The most important pathophysiological factors affecting the occurrence of gastrointestinal symptoms are ischemia and mechanical damage to the intestines, as well as the secretion of neuroendocrine substances. The diet before physical exercise is also one of the most significant factors related to the appearance of gastrointestinal symptoms. Avoiding the intake of fat, caffeine, protein, fiber, non-steroidal anti-inflammatory drugs and dehydration before performance is one of the suggestions for preventing runner’s diarrhea. There are new recommendations for athletes, such as avoidance of fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs) and the intake of multiple transportable carbohydrates. It seems that a short-term gluten free diet has no effect on the performance of athletes but further research is needed. Mechanisms of runner’s diarrhea are still poorly understood, so more research needs to be conducted to improve the recommendations to runners.
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